1. Field
Embodiments of this invention relate to a touch screen panel.
2. Related Art
In recent years, along with the development of the electronics industry, display devices, such as a liquid crystal display, an electroluminescent display, and a plasma display panel having a quick response speed, low power consumption, and an excellent color reproduction rate, have been in the spotlight. The display device is used for various electronic products such as televisions, monitors for computers, notebook computers, mobile telephones, display units for refrigerators, personal digital assistants, automated teller machines, and the like. In general, the display device interfaces with various input devices such as a keyboard, a mouse, and a digitizer. However, when a separate input device such as a keyboard, a mouse, or digitizer is used, a user is required to know how to use the separate input device, and as the separate input device occupies space, customer dissatisfaction is increased. Therefore, there is increasingly a need for a convenient and simple input device that can reduce erroneous operation. Also, there is a need for a touch screen panel in which a user can input information by directly contacting a screen with a finger or a pen.
Since the touch screen panel has a simple configuration, which minimizes erroneous operations, the user can perform an input action without a separate input device, and can quickly and easily manipulate through contents displayed on a screen.
Touch screen panels are classified into a resistive type, a capacitive type, an electromagnetic type according to a detection method of a touched portion. The resistive type touch screen panel determines a touched position by a voltage gradient according to a change of resistance in a state where a DC voltage is applied to metal electrodes formed on an upper plate or a lower plate. The capacitive type touch screen panel senses a touched position according to a difference in capacitance created in an upper or lower plate when the user physically contacts with a conductive film formed on the upper or lower plate. The electromagnetic type touch screen panel detects a touched portion by reading an LC value induced as an electromagnetic pen touches a conductive film.
Hereinafter, a capacitive type touch screen panel in the related art will be described with reference to FIGS. 1, and 2A to 2C. FIG. 1 is a plan view illustrating a capacitive type touch screen panel in the related art, and FIG. 2A is a sectional view taken along the line I-I′ in the touch screen panel in FIG. 1, FIG. 2B is a sectional view taken along the line II-II′ in the touch screen panel in FIG. 1. FIG. 2C is a sectional view taken along the line D-D′ in the touch screen panel in FIG. 1, and is a schematic diagram illustrating a state where undesired conductive particles M positioned on an insulation pattern between electrode patterns causes a first electrode and a second electrode to be short-circuited.
Referring to FIGS. 1, and 2A to 2C, the capacitive type touch screen panel in the related art includes a substrate 10, a plurality of first electrode patterns 40 formed on the substrate 10 and arranged in parallel in a first direction (for example, an X-axis direction), and a plurality of second electrode patterns 50 arranged in parallel in a direction (for example, a Y-axis direction) intersecting the first electrode patterns 40. The touch screen panel also includes insulation patterns 30 which are formed at intersections of the first electrode patterns 40 and the second electrode patterns 40 and electrically insulates the first electrode patterns 40 and the second electrode patterns 50, bridges 20 which are formed on the substrate 10 under the insulation patterns 30 at the intersections of the first electrode patterns 40 and the second electrode patterns 50 and connect the neighboring first electrode patterns 40, and second electrode pattern connection parts 60 which are formed on the insulation patterns 30 and connect the neighboring second electrode patterns 50.
In the capacitive type touch screen panel in the related art, the insulation patterns are formed on the bridges 20 disposed on the substrate 10, and thereby step differences A are formed on the insulation patterns 30 due to the bridges 20, as shown in FIG. 2B. In such a structure, the insulation patterns 30, as shown in the enlarged portion of FIG. 1, typically have a linear form between the first electrode patterns 40 and the second electrode patterns 50. A distance between the first electrode pattern 40 and the second electrode pattern 50 is considerably short and further the insulation pattern 30 has a short path due to the linear form, and thus undesired conductive particles M, which is generated in a process of patterning the first and second electrode patterns 40 and 50, or subsequent processes, are accumulated on the step differences A along a boundary surface 30a of the insulation pattern 30. In this case, as shown in FIG. 2C, there is a problem in that the first electrode pattern 40 and the second electrode pattern 50 are short-circuited.